In brief, psychics read energy and mediums communicate with spirits. For more clarity, "psychics" obtain information by intuitively reading energy (for instance, your aura or Universal energy). They might also use divination tools, such as tarot cards, crystals, tea leaves, etc. Alternatively, "mediums" are also able to read energy but generally focus their readings on communicating with spirits (deceased loved ones in spirit or spirit guides). NOTE: Although we often shorten the phrase "psychic mediums" to just "mediums," all mediums are both psychic and mediumistic (it's just easier to shorten it).
If you are seeking information about your career, relationships, finances or anything regarding past, present or future insights, a reading with a psychic is best. However, if you are seeking to communicate with a deceased loved one or one of your spirit guides, a reading with a medium is best.
Readings by telephone are in many ways better than readings in person because the psychic or medium cannot deduct clues from your appearance, facial expressions or body language. Since you might not live in the local area of a gifted psychic or medium who interests you, be sure to consider phone readings as an alternative. Don't limit your options merely because you have the limiting belief that an "in person" reading is better. It isn't.